Before, in the case where a plurality of electrical wires in wire harnesses to be arranged in a motor vehicle are connected to one another, insulation sheaths of the electrical wires are stripped to expose core conductors, the exposed core conductors are connected to one another by means of welding, soldering, or crimping by crimping terminals to form a spliced portion. Since the core conductors or crimping terminals will be eroded if water adheres to the spliced portion, wire harnesses to be arranged in an engine compartment in a motor vehicle, which is a water-receiving area, have spliced portions with a waterproofing function.
The present applicant has disclosed a waterproofing process in JP HEI 7(1995)-184308 A (Patent Document 1). FIGS. 5A and 5B show a watertight structure 1 for a spliced portion on electrical wires in Patent Document 1. FIG. 5A is a perspective view of a prior art resin mold for producing a prior art watertight structure for a spliced portion. FIG. 5B is a longitudinal section view of the prior art watertight structure for the spliced portion.
In the watertight structure 1, core conductors a and b are exposed from electrical wires W1 and W2 constituting wire harnesses, a spliced portion 2 that is formed by crimping the exposed core conductors a and b by crimping terminals is inserted into a resin mold 3, and a watertight agent 4 is filled in the resin mold 3.
The resin mold 3 is formed into a box-like configuration elongated longitudinally and having an open top. A bottom wall 3a of the resin mold 3 is provided on longitudinal opposite side ends with side walls 3b-1 and 3b-2 for receiving the electrical wires W1 and W2 and on opposite lateral sides with side walls 3c. One side wall 3b-1 is provided in an upper end with a single electrical wire threading groove 3d-1 that corresponds to a size of the electrical wire W1 while the other side wall 3b-2 is provided in an upper end with two electrical wire threading grooves 3d-2 and 3d-3 that correspond to sizes of the electrical wires W1 and W2. The sizes of the respective electrical wire threading grooves 3d-1 to 3d-3 are set to be dimensions in which the respective electrical wires W1 and W2 are fitted closely in the respective grooves.
Patent Document 1: JP HEI 7(1995)-184308 A